Hey all,
Spent the best part of 2 days reading this forum in attempt to glean as much info as I can on my prospective 35i / 35is purchase.
So far I have ascertained the following as known issues (although not necessarily particularly prevalent). I have listed in order of most expensive to least (assuming car does not have a warranty):
- DCT gearbox rattle / failure
Only aware of 2 or 3 instances where owners have had these replaced under warranty. Rattling / noisy seems to be the complaint. Dread to think what one would cost out of warranty.
A common occurrence on the 296 (1st pic), less common on the 326M (2nd pic) style alloy wheels but all the 19" seem to be affected much more then the 18". Cracking is typically on the inside rim so not easy to spot from the roadside. Ditching the RFT (run flat tyres) may help to prevent cracking as the runflats have a very stiff side wall. Budget at least £500 per wheel if you have to fund it yourself, or repair may be an option for £50-£70 each if you want to keep 'em.
These seem to leak fuel when closed which commonly causes poor running, particularly poor starting from cold with lots of spluttering. Looking at least £200 x 6 + fitting. BMW seemed to have revised these as the years have gone by so the most recent ones may be more reliable.
- Leaking adaptive suspension
Seems to be fairly isolated but one or two have had shock absorbers replaced due to fluid leakage so inspect carefully with the wheel removed if your warranty is coming to an end. Noises / clunks from the suspension also reported but these seem to be more likely to be bushes on the rear anti-roll bar.
- HPFP (High pressure fuel pump)
Most common complaint for this seems to be noisy rather than actually failing and stopping the car. Not sure of exact price but not cheap!
A common failure point on many cars (not just BMW) and it seems the E89 is not excluded. Not a difficult DIY to replace and I think around £60 or so each. Misfire on acceleration and poor performance once warmed up seem the most common complaint.
- LPFP (low pressure fuel pump)
The E89 uses a 'primer pump' inside the tank to send fuel up to the HPFP. You can often hear it start when you turn on the ignition. Again, seems like noise issues are the most prevalent complaints. Most dealers seem to needlessly change these when trying to fix cold start problems, only to then find it was the injectors all along.
- Rattling wastegate actuators
Again, not sure how this manifests itself in terms of fault symptoms but fairly widely reported. There are also some pressure transducers and a filter related to the turbo which have been noted to fail and cause an overboost malfunction (EML light on dash) - see here
viewtopic.php?f=45&t=87475
Not sure of the fix for the wastegate, maybe just an annoyance rather than a problem?
- Electric handbrake failure
Usually lock on and can't be released which makes it a bugger to get the car to a garage. Seems to be related to early 'buggy software' in connection with the wheel speed sensor which perhaps isn't very well written. New software flash of the handbrake ECU seems to sort it. Most have to physically remove the electric actuators (small servo motors on the rear hub) to be able to move the car
- Water ingress into boot / rear light cluster
VERY common reported fault and of course not restricted to the 35i. The BMW sealant degrades badly at around 5 yrs or so and requires all the rear sealant strip around the boot to be removed, cleaned, gutter sealant added and refitted. The rear light cluster seal also seems badly designed, resulting in misting and corrosion inside the assembly. Aftermarket ones are available from Euro Car Parts for a modest amount and seem to be better designed, otherwise it's a strip down, clean and seal properly before refitting. Note there was a recall for some aspects of water ingress into this area (vents?), and you can tell if this has been done by the presence of a green trim clip in the boot area.
I think that's all the stuff I've read about. Please feel free to add / comment and correct if I got anything wrong or missed anything.